Apparatus for handling and applying plaster



y 1951 P. c. BAUMANN 2,552,763

APPARATUS FOR HANDLING AND APPLYING PLASTER Filed May 22, 1948 2 Sheets-Sheet 1 FIG. 1 s

INVENTOR. 73M C, 6W- BY ATTORNEY May 15, 1951 p BAUMANN 2,552,763

APPARATUS FOR HANDLING AND APPLYING PLASTER Filed May 22, 1948 2 Sheets-Sheet 2 59 2 O INVENTOR.

54 v I I 52 @0. 2 m

ATTORNEY Patented May 15, 1951 APPARATUS FOR HANDLING AND APPLYING PLASTER Paul C. Baumann, Milwaukee, Wis.

Application May 22, 1948, Serial No. 28,608

1 Claim. 1

The invention relates to a method and apparatus for the handling andapplying of plaster.-

In the usual method of handling and applying plaster, the plaster ingredients are mixed either by hand or in a machine mixer, the mixed plaster discharged into hods and carried to a mortar board from which it is taken by the plasterer and applied to the wall to be surfaced. This method involves considerable hand labor and also considerable difficulties in the handling of the raw materials for the mixer.

The object of the present invention is to provide a new and improved method and apparatus for handling of plaster whereby the mixed plaster is conveyed without manual handling to the place where it is to be applied, and further to an improved method of applying the plaster by spraying the same on the wall to be coated, thus eliminating considerable hand labor. More particularly, by the present method, the plaster ingredients are mixed in a portable motor driven mixer located where the raw materials may be readily delivered to it, the mixed plaster is then chuted to a pressure pump where it is further mixed under pressure and forced into a delivery conduit which leads to the place of use where it may be either delivered as wanted to a mortar board or preferably applied to the wall by the plasterer by spraying the stream of plaster onto the wall to be coated. Not only does this method effect a great saving in time and labor, but I also find that when the plaster is mixed under pressure in the pump after its customary mix in the usual mixer, the ingredients are so intimately intermixed that less neat plaster is necessary and more sand may be used to produce as good or bet ter plaster composition than is customarily used.

The invention further consists in the method and apparatus hereinafter described and more particularly defined by the appended claim.

In the drawings:

Fig. 1 is a vertical sectional view taken on the line l-l of Fig. 3 of apparatus embodying the invention and used in carrying out the method of handling plaster, parts being broken away and parts being shown in section;

Fig. 2 is a detailed horizontal sectional view taken on the line 2-2 of Fig. 1 together with other parts not shown in Fig. 1;

Fig. 3 is a side elevation view of apparatus embodying the invention;

Fig. 4 is a schematic view of apparatus embodying the invention set up for use in carrying out the method;

Fig. 5 is a horizontal sectional view taken generally along the line 5-5 of Fig. 4 showing a trailer housing the major portion of the apparatus.

Referring to Figs. 4 and 5 of the drawings, the numeral 1 designates a trailer of the type having a fifth wheel connection with its automotive tractor vehicle and provided with an end opening 8, a side opening 9, and a top opening, the doors ID for which are indicated in open posi tion in Fig. 5. The interior of the trailer has a sand bin ll supplied with sand through the top opening and a plaster storing space l2 accessible through the opening 8. Between the bin H and the space l2 there is a space for the major portion of the apparatus.

The apparatus includes a plaster mixer l3 of the usual mortar mixer open type driven by an internal combustion engine or other suitable prime mover or motor housed within the housin It, the mixer being supplied with water from a measuring tank 15 through a pipe l6 and having a discharge outlet I! closed by a door l8 carried by a pivotally supported shaft l9 under the control of the operator through a handle 20. By

-' the term usual open type mixer I mean a housing open to atmosphere and having a power driven rotary bladed agitator mounted therein. By the term open type I mean one in which the materials are not mixed under pressure. The engine is controlled by a manually operable control 2! and the inlet valve (not shown) for the measuring tank being controlled by a member 22. All of the above parts are of usual or standard construction, the mixing drum 23 having the usual top opening 24 into which sand and neat plaster or other plaster ingredients may be introduced, this whole assembly being mounted on a frame 25 including uprights 26, which frame. is adjustably supported above the floor of the vehicle by a plurality of leveling jacks 211.

The outlet I1 is in a position to discharge into a hopper or chute 28 supported by frame members 29 above the floor of the vehicle and discharging by gravity through an outlet 35 into the inlet 3| of a pressure pump 32 preferably of the screw type having a screw type rotor 33 whose shaft 34 passes through a stuffing box including a gland nut 34' and has an exteriorly disposed portion journalled in a bearing 35 and carrying a sprocket 36 connected by an endless chain 31 with a sprocket 38 mounted on a shaft 39 journalled in bearings 40 and connected to a drive shaft 4| by any suitable clutch as the jaw clutch 42 shown, one jaw 43 of which is slidably keyed to the shaft 39 at 44 and carries a grooved collar 45 connectdow 53 from the trailer parked at the curb of a street adjacent the building containing said room, as shown in Fig. 4. In order to permit themixed plaster to be distributed to different portions of the work site the conduitr5i is provided with multiple outlets 59, eachoutlet having a shut off valve 55 of any suitable construction. With the above apparatus, the plaster ingredients and the necessary water are charged into the mixer 13 by-an attendant Within the trailer, and aftermixing, the door I8 is opened and the mixed plaster discharged through the outlet I 1 into the hopper 28 from which it flows by gravity through its outlet 38 into the inlet 3| of the pump, and as the screw 39 is rotated, the mixed plaster is carried forwardly through the pump chamber and put under pressure, and at the same time the ingredients are further and intimately mixed and forced out through the conduit 5i and discharged through one or more of its outlets either to a mortar board or boards from which it may be removed by the plasterer as needed or to a flexible pipe or conduit 56 connecting said conduit 5! with a suitable spray nozzle 5? from which it may be sprayed by the plasterer directly onto the wall until the desired thickness of plaster is deposited thereon. Where spraying is used, I preferably provide a nozzle using compressed air as a propellant and distributor, and. for this purpose each nozzle 57 has a flexible air hose 58 connected to one of a series of branch outlets 59 of a fitting 60 connected by a supply hose 61 with a compressed air storage tank or reser voir 62 which is supplied with com-pressed air through a pipe connection 63 with an air compressor 64 driven through a chain and sprocket connection 65 by any suitable prime mover 66 such as an internal combustion engine or electric motor. ilhe outlets 59 may be controlled by suitable cut off valves 6'! and each nozzle 57 may also have out 01f valves 66 and 69 for controlling the mixed plaster and air supplied thereto. In order to prevent damaging pressures building up in, the conduit 5| if its outlet or outlets are cut off, I provide means operated by the pressure of the mixture for releasing the clutch 42 from its motor drive shaft, said means comprising a conduit 76 containing hydraulic fluid and one end of which is connected to a cylinder ll andthe other end to a cylinder 12. The cylinder ll communicates with the outlet 49 of the pump and has a piston'l3 slidably mounted therein movable in one direction by fluid pressure and in the other direction by an adjustably tensioned pressure regulating spring M. The. cylinder 72 has a piston 75 slidably mounted therein and having a piston rod i6 extending exteriorly thereof and operatively pivotally connected to the intermediate portion of the clutch lever 46, said piston being associated with a return spring 71. With'this arrangement if the pressure of the mixture should reach a predetermined maximum in the pump chamber clue to shutting oil the outlet of the conduit El, then the mixture within said chamber operating on the piston 73 will move the same outwardly against the pressure of the spring 74 and put pressure on the fluid in the conduit 10 which pressure is transmitted to the piston 75 causing its outward movement against the pressure of the spring 71 and as a consequence movement of the clutch lever 46 to clutch release position, thereby stopping the pump. Of course, the clutch lever 46 may also be manually operated to shut on the pump drive.

With the above construction not only are the labor and inconveniences usually encountered in mixing and carrying the mixed plaster to its point of use eliminated, but I also find the mixing in the mixer and the additional mixing of these materials under pressure by the pump is so superior to that of the usual method of mixing in the usual open type mixer alone that less plaster and more sand may be used to produce a mixture as good as or better than the usual plaster compositions, thereby effecting a considerable saving in the cost of raw materials. For example, the usual practice is to use twelve to fourteen No. 2 shovelfuls of sand to every hundred pounds of neat plaster, whereas with my method sixteen to seventeen No. 2 shovelfuls of sand may be used to every hundred pounds of neat plaster.

It will be noted that the method above described may be used with the regular plaster mixes or with so called finish plaster mixes.

' It is further to be noted that the apparatus above described provides a steady and continuous flow of the mixed plaster composition deliv ered either to a mortar board or to a spray nozzle.

I desire it to be understood that this invention is not to be limited to any specific details except only where the same are included in the claim.

What I claim as my invention is:

In an apparatus of the type described, the combination of a motor driven pump and mixer for remixing plaster composition under pressure and delivering it as a stream under pressure, a gravity discharge means for delivering mixed plaster to said pump, a delivery conduit connected with the outlet of said pump, disconnectible drive means for said motor driven pump, and mixture pressure controlled fluid pressure operated means connected with the outlet of said pump and with said disconnectible drive means for stopping the operation of said pump when the pressure of the plaster composition at its outlet reaches a predetermined maximum.

PAUL C. BAUMANN.

REFERENCES CITED I The following references are of record 

